Complement fixing antibody to varicella-zoster virus in different age groups and after zoster.

The titer of complement fixing antibody to Varicella-Zoster virus was studied in sera from 215 normal persons living in Padua and its province and from 39 Zoster patients. About 74% of sera from normal persons aged 21-80 years had antibody titers larger than or equal to 1/4. Lower titers were present in the age groups 1-20 years and 81-90 years. Sera from Zoster patients had high titers from the second week following the onset of the rash. They were still comparatively high until the fifth month, sometimes remaining detectable even after a year or more.